Torquing a nut onto a bolt to hold an object between the nut and the head of the bolt is common art. Because this is such a fundamental joinder, the art is replete with improvements both to the nut and to the bolt. Such joinders are commonly driven by tool engagement either at only one end or at both ends of the fastener. What all of them have in common is the exertion of a torque between the nut and the bolt to tighten the joinder.
Similarly, torque tools of widely varying characteristics are well known. They have in common the engagement of both parts of the joinder if the bolt can turn, or sometimes only of the nut if the bolt is otherwise restrained against turning. Tools which engage the nut and the bolt separately, and tools which drive both but from only one end of the joinder are also known. Whatever the situation, it is common practice to engage one or both parts of the joinder and to apply torque to set it. Torque may be applied from a power source such as a drill motor, or by means as simple as a hand wrench. In all such cases a tool is engaged to the joinder and a moment is somewhat exerted to tighten it.
Large numbers of such joinders are used every day with complete acceptance by the trade. It is no disadvantage for a workman standing on a floor or on some support to move a tool from joinder to joinder, and for him either to actuate a power wrench or to lean on a manual wrench.
However, there exist potential applications where a power tool cannot conveniently or effectively be used. For example, in space applications the tool itself consumes rocket throw weight to put it in place. Throw weight is inordinately expensive. After it is placed in space, then in operations outside the space craft the wrench must be carried around and manipulated. It exerts a counter torque which must somehow be resisted. One unacceptable situation is for the torque to be exerted on the operator so that he tends to rotate in a counter direction and must himself be restrained. Use of a simple hand wrench presents similar problems. Wrenches which keep the counter torques within themselves tend to be heavy.
It is an object of this invention to provide a joinder which has inherent torquing means that are inherently in the joinder and are ready to apply the torque needed to set the joinder. These can function with no more than the release of a latch. This is the self-driving nut of this invention. The source of torquing energy can conveniently be included in an appropriate envelope in the joinder, the "winding" energy being applied earlier, and adds some weight to the joinder which is justifiable by the other problems which it solves. The nut is present at the joinder site and is actuatable without requiring exertion of torque from outside of the joinder.